Pawl and ratchet device



Jan. 19, 1937. l

c. H. vTAYLOR PAWL AND RATGHET DEVICEl 2 Sheets-Sheet 1 Filed oct. z', 1935 INVENToR ATTORNIY Jan. 19,1937. c* H, kil-Amonv 2,067,990 l PAwL .um RATGHET. brivwE Filed oct, 2, 1255 aSheets-sheef 2 par."

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Patented Jan. 19,V i937 [PATENT OFFICE PAWL AND :wrom-:T DEVICE charles n. Taylor, North canton, ohio, assignmto The Hoover Company, North Cantn,v Ohio a. corporation of Ohio Application ootobor 2, 1935, serial No. 43,131

-s claims. (ci. '1a- 155) This invention relates to improvements in suction cleaners and more 'particularly to means for adjusting theheight of the nozzle oi a suction cleaner with relation to the surface of the floor ,covering to be cleaned.

'I'he object of the invention is to provide` a simple and eiective mechanism for accomplishing the desired adjustment either for the purpose of gauging the nozzle height to the particular kind of oor covering or for elevating the nozzle and associated parts above or out of contact with the floor covering when the cleaner is being operated with the auxiliary cleaning tools and connecting hose.

Although nozzle adjusting devices have long been associated with suction'cleaners, the present invention is characterized by a foot actuated pedal and a novel type of ratchet mechanism operating the primary adjusting members in such manner as to obtain the required adjustment with e the least physical effort and without unduly complicating the structure of the cleaner.

The preferred embodiment ofthe invention is disclosed in the accompanying drawings in Which- Figure-1 is a view in side elevation of a suction cleaner with portions broken away to show the nozzle adjusting mechanism.

Figure 2 is a bottom plan view oi the cleanerv 30 showing the nozzle mechanism in section.

Figure A3 is an enlarged detailview in section taken on line 3--3 of Figure 2.

Figure 4 is a view of thevcleaner in side elevation'similar to Figure 1 showing the nozzle in lowered position and the foot pedal in' its depressed position. Figure 5 is a view similar to Figure 4 showing the cleaner with the nozzle in elevated position. Figures 6, 7 and 8 are enlarged views in section taken on line 6-6 of Figure 2 and showing the successive positions of the parts of the adjusting mechanism during each downward stroke of the `ioot pedal. l l

The suction cleaner to which the adjusting mechanism is applied comprises in .general a wheeled casing I adapted to bev maneuvered over theiloor by a. handle having a forked extremity or bail 2 pivoted to the casing. The forward por- 50 tion of the casing constitutes the nozzle 3, the same having a wide downwardly opening slot 3a through which the air is drawn by suction malntained by a motor driven fan 4 mounted within the casing. Also driven by the fan is a cylindric 55 agitator 5 extending lengthwise o f the nozzle .180 degrees by a suitable pin and slot connec- -.lever I3 is mounted on theishaft I2 immediately adjacent the side wall of the housing, said lever vopening and having helically arranged beater bars ablyconsisting of a pair of iront wheels 6, 6, lo- 5 cated just rearwardly of the nozzle slot 3a and adjacent opposite ends thereof and a double wheel caster assembly .1 mounted centrally and at the rear of the casing I.

As a, preferable and suitable mounting for the front wheels, a shaft 8 is journalled within thel nozzle portion 3 of the casing just rearwardly of the nozzle opening 3a and above the axis of the wheels, said shaft having its end portions bent at right angles to provide crank arms 8a', 8a terminating in stub shafts on which the wheels 6,` 6 are journalled. Suitable bearings 9, 9 support the central portion of the shaft 8 for a rocking move- Yrnent limited to an arc of something less than.

tion 9a in one of the bearings 9 as shown in Figu res 2 and l3.

As clearly shown in Figure 1 the crank arms 8a, 8a normally assume a position of rearward inclination to the vertical plane of the axis of the shaft 8, being held in that position by the action of a torsion spring III surrounding the shaft with one end anchored thereto and the other end bearing against a shoulder Iaon the casing. Hence, by swinging the crank arms forwardly or counter-clockwise against the tension of the spring 'I 0, the nozzle will be elevated as the wheels approach a vertical position.

The range of adjustment is thus conned to arc between the vertical and rearwardly inclined positions of the wheel supporting crank arms 8a, 8a and the mechanism about to be described functions to obtain and maintain this adjustment.

'Ihe adjusting mechanism is preferably mounted `on one side of the casing I and partially, if not 40 almost completely `enclosed within a separate housing I I, preferably cast integral with the casing I just rearwardlyof the nozzle portion 3. The support for the adjusting mechanism located within the housing I I is a tubular bearing or stub shaft I2, supported at one end only in the outer vertical wall of the housing and projecting inwardly therefrom. y

As clearly shown in Figure 2 a foot actuated projecting through a slot Il in the rear 'wall of said housing and terminating in a pedal I3a immediately'exterior thereof. Coiled around the .stub shaft I2 between the lever I3 and the side 55 wall of. housing II is a coil spring I5 having one end anchoredjin the housing wall and the other end to the lever, thereby acting to holdthe latter in its elevated position. Incidentally, the lever I3 has a short arm I3b on the opposite side of the stub shaft from. its pedal extremity, said arm '13b serving as a stop to limit the depression of to be confused with another coil spring associated with the pedal operated ratchet mechanism and presently to be identified.

The ratchet mechanism comprises a pair of discs IS and I1 mounted substantially face to face to rotate about the stub shaftl I2, the disc I6 being journalled en the shaft just inwardly beyond the foot actuated lever I3 and separated therefrom by a spacing collar I8. The outermost disc I6 is preferably flat, whereas the disc I1 is located at the extreme inner end of the stub shaft I2 and is provided with an integral shaft Ila having bearing in the central bore of the stub shaft I2 and held in place by av screw and washer -as at I1b (Figure 2).

Moreover, the disc I1 is dished or concave at its center, whereas the disc I6 is iiat, thereby bringing the marginal portions of the two discs 'into contact with each other and providing a space on the shaft for a torsion spring I9, consisting of two coils or turns surrounding the shaft I2 and having its ends inserted througha hole in each disc as shown in Figure 6. Moreover, these discs are interconnected by a pin 20 carried by the disc I6 and engaging an arcuate slot 2| in the other disc I1, saidslot describing a. relatively small arc, thereby limiting the relative rotation of the discs Y to a few degrees, this arc being predetermined by the spacing of the teeth on the vrdiscs as will presently be explained.

The peripheries of both discs are surrounded by teeth complementing each other in number and pitch but differing in shape and depth. More definitely, the teeth on the outermost disc I 6 are in the nature o f ratchet teeth while the teeth on the innermost disc I1 are more in the nature of clutch or cam teeth. For convenience in distinguishing the two discs hereafter, they will accordingly be termed the ratchet disc I 8 and the clutch disc I1. Moreover, the teeth on the ratchet disc I8 may be distinguished by their shortness radially and the beveled edge at the forward end of each tooth, whereas the teeth on the clutch disc I1 are substantially square, having radial front and rear edges thusforming uniform U-shaped notches therebetween.

Now, coasting with the ratchet disc I8 is a pawl 22 having the form of a link pivotally mounted on the foot operated lever I3 and having a detent 22a at its free end engaging the ratchet disc I6 at a point above the axis thereof. A coiled torsion spring 23, surrounds a pivot pin 22h on which the pawl is mounted and, anchored .at its ends to the pawl and lever, yieldingly holds the former in contact with the ratchet teeth.l Y

To complete the ratchet mechanism assembly a spring actuated keeper or latch member 24 co- "acts with both discs, at a point spaced in a the'vertical'wall oi' the housing Il and depending therefrom vhas a relatively broad detent 24a at its free end, adapted to engage the teeth of both ratchet and clutchv discs. `A 0011 spring 26` mounted on the pin 25 acts to press the latch member against the discs.

And finally, a link 21 pivotally connected at one end to-a pin 28 eccentrically positioned on the outer face of the cam disc I1, extends horizontally and forwardly through a vertical slot in a transverse wall 29, (Figure 2), separating the forward end of the housing I I from the compartment or-space wherein the Wheels B and their supporting crank arms 8a are located. The forward end of the connecting rod 21 has pivotal connection with a short arm `3l) extending at right angles from the crank arm 8a at the adjacent end of the wheel carrying shaft 8.

Now, it is apparent that in the rotation of the ratchet disc I1, endwise movement will be im- -pa'rted to the connecting link or rod 21 and ii' this movement be forwardly the wheel supporting crank arms 8a will be shiftedvtoward a vertical position carrying the wheels forwardly and thus elevating the nozzle to a greater height above the floor level as is seen by comparing Figures 4 and 5. Contrarywise, by shifting the rod 21 rearwardly the tension of the spring I0 on the wheel supporting shaft' will act to swing the crank arms rearwardly, thus depressing the wheels and lowering the nozzle. v

From Figures 6, 7 and 8, the action of the ratchet mechanism in ,accomplishing the nozzle adjustment will be readily understood: From the normal and elevated positionof the foot lever I3 (Figure 6) in which it contacts with the upper end of the guide slotA I4 and held by the action of the spring I5, the first movement -upon applying pressure on the pedal is a slight turning of the ratchet disc I6 forwardly in a clockwise direction relative to the cam disc Il, this relative movement being limited to the small arc described by the pin 20 in shifting fromi' the rear to the forward end of the slot 2|, as own in Figure 7. .The primary result of this initial relative movement between the rdiscs it to lift or radially shift the latch member 24 outof contact with bottom of the notch to the top edge l.of the advancing ratchet tooth by the cam. action of the latter as its beveled leading edge rides under a complementary beveled edge 24D of the latch member.

, This preliminary shifting of the latch member Fig. 8) the following movements occur: First, the

ratchet disc I0 is rotated further in a clockwise direction through an arc of about 4i degrees by the pawl 22; second, the cam disc 'I1 is rotated with the ratchet disc and through the same arc by virtue of the pin and slot connection therebetween; and third, the latch member 24 is lifted completely out of contact with the ratchet disc IB by the cam action 'of the advancing tooth of the clutch disc I1, thus causing the latch member to slide over said clutch tooth and drop into the next notch and into contact with the next ratchet tooth as shown in Figure 8. f

In the meantime, however, the disc I1. having been rotated with. the disc I6 through the arc equal to the throw of the depressed foot lever I 3, has imparted an endwise movement to the connecting link 21 which in turn is converted into 75 member 24 slips back into 's to that of Figure 6. In

lthe nozzle height adjusting movement of the wheel supporting cranks, as already explained.`

But it will be-observed that the'latch member 24 has been shifted to the next notch in the clutch disc i1 so that the foot pedal I3 can now the next racthet tooth, while the ratchet disc I6 being momentarily released by the pawl, rotates in a counter-clockwise direction through the arc permitted by the travel of the pin 20 from the forward to the rear'end of the slot 2i, that is, from the position of Figure 8 to the position oi' Figure 6, and in this same movement the latch full engagement with the ratchet disc, also, from the position of Figure brief, the act of releasing the foot pedal automatically restores the ratchet mechanism toits initial or normal position and in readiness for furtherv operation of the foot pedal in case repeated depressions thereof are required to obtainthe desired height adjustment of the nozzle.

Thus it will be seenl that with each depression of the foot pedal, the discs advance through a predetermined arc and always in the same direction, the adjustment being either upwardly or downwardly depending on crank circle the pin 28 is traversing at the particular time the adjustment is being made. And this accounts for the fact that it may be necessary to operate the ratchet mechanism repeatedly until the desired nozzle height adjustment is obtained.

Having set forth the preferred-embodiment of the invention, l

I claim:

1. In a mechanical movement for imparting an intermittent rotary motion, the combination of a ratchet ldisc and a clutch disc rotative about a common axis and having limited relative rotation through a small arc, tension means acting to hold said discs at one extremity of their relative' rotative movement, an operating lever including a pawl -engaging teeth on said ratchet disc and operative to rotate said discs through a predetermined angle in one direction during each operating stroke thereof, a spring-pressed latch member engaging teeth on said clutch disc to normally hold the same against rotation, said ratchet -disc acting in its initial rotation to displace said latch member and permit the same to pass over one of said clutch teeth with each operating stroke of said operating member.

2. In a mechanical movement for imparting an intermittent rotary motion, the combination of a ratchet disc and a clutch disc rotative about a common axis and having limited relative'rotation through a small arc of predetermined angularity, tension means acting to hold said disc at one extremity of the arc representing their relative rotative movement,an operating lever including a.

pawl engaging peripheral teeth on said ratchet disc and operative to rotate said discs through a predetermined angle in one direction during each operating stroke thereof, a spring-pressed latch member engaging teeth on said clutch disc to hold the same against rotation in the opposite direction, said ratchet teeth acting on said latch member during the initial relative rotation of .said

disc. to release .the same from latching engagement with said clutch disc with each stroke` of said operating member and to permit it to 'rewhich portion of its.

sume its' latching engagement with said clutch ldisc'during the return movement of said operating member 'to its initial position.

3. In a mechanical movement for imparting intermittent rotary motion, the combination of a ratchet disc and a clutch disc-mounted for rotation about a common axis, an operating pawl lever acting to rotate said ratchet disc through a given arc with each stroke thereof, said ratchet disc having teeth withsloping leading edges and said clutch disc having substantially square teeth projecting beyond the said ratchet teeth, a spring-pressed latch member engaging said ratchet disc and provided with a detentengag'ing said clutch teeth to prevent the backward rotation of said discs after each stroke of said operating lever, lsaid clutch and ratchet discs having pin and `A slot connection permitting a limited relative movement through a small arc' during the initial rotation thereof to effec* the radial displacement of said latch member by said ratchet teeth, whereupon' the furtherrotation of said disc permits the latch member to pass over one ofthe clutch teeth into contact with the top of the following clutch tooth, andal torsion spring acting to rotate the discs yrelative to each other in the direction opposed to their initial4 relative rotation upon the whereby the Tparta arereturnedtb their normal positions. 1.

4. A ,mechanical movement'for imparting intermittent rotary motlonkthe combination of a ratchet disc and a clutch disc mounted for rotation about a common axis, an operating lever acting to rotate said discs through a given arc release of said operating leven.

during each operating stroke thereof, said ratchet and clutch discs having complementary teeth, a spring-pressed latch member engaging the teeth of said discs td prevent their backward rotation after each forward movement by 4said operating lever, said ratchet teeth being relatively short a'nd having sloping leading edges and said clutch teeth being substantially square and projecting radially beyond their complementary ratchet teeth, said discs having pin and slot connection whereby the same have a limited relative Amovement through a small arc permitlting the ratchet disc to rotate slightly in advance oi' said clutch disc during the initial rotation oi said discs, to displace said latch member radially from the bottom to the top of one of said ratchet teeth', whereupon in further rotation of said discs the latch member passes over the complementary clutch tooth and into latching ensagement .with the following clutch tooth, and a torsion spring acting upon the release of said operating lever to shift the discs relative to each other in the direction opposed to their normal direction of rotation whereby the complementary ratchet tooth is advancedto its normal posi'- ticn.

5. In. a mechanical movement for imparting intermittent oscillating motion to a crank arm.

the combination of a pair of discs rotatively mounted in close proximity on a common axis and having pin. and slot connection permitting ltheir angular displacement throughout a relatively small arc, a torsion spring acting to normaily retain discs at one extremitytof their relative angulardisplacement, said discs having substantially the same-pitch diameter and complementary peripheral. teeth, the teeth of one of said discs being shorter and sloped at their leadthe other. disc being subating pawl lever engaging the teeth ci the first mentioned Idisc whereby said discs are rotated through a predetermined arc during each stroke of said operating lever, a spring-pressed latch member engaging the teeth of both of said discs, the shorter teeth of the rst mentioneddisc acting to displace said latch member radially outward from the complementary tooth of the other disc during their angular displacement at the commencement of the operating stroke of said pawl lever, thereby permitting said latch member to successively pass over the teeth of said last mentioned disc with each stroke of said pawl lever and to eiect its normal latching. engagement with the following clutch tooth upon the angular displacement of saiddlsc in the opposite direction under the tension ci the said torsion spring upon the completion of each operat-` ing stroke, and a rod connecting said last mentioned disc with said crank arm. 'u

6. In a mechanical movement for imparting intermittent oscillating motion to a crank arm,A

the combination of a pair oi discs rotatively mounted in close proximity on a common axis and having pin and slot connection permitting their angular displacement through 'a relatively small arc, a torsion spring acting to normally retain said discs in one position vof their relative angular displacement, one of saiddiscs having peripheral ratchet teeth, an operating lever having a pawl engaging said ratchet teeth and operative to rotate said disc through a predetermined angle duringv each operating stroke thereof, the other said disc having substantially square clutch teeth complementing said ratchet teeth and projecting beyond the same, a spring-pressed latch member engaging the teeth ot said discs, said sion of said torsion spring restores the discs to their normal positions when said operating lever is released at the completion of each operating stroke, and a connecting rod between said clutch disc and said crank arm.

7. In a mechanical movement for imparting intermittent rotary motion, the combination of a pair of discs rotative about a common axis and having limited relative rotation through a relatively small arc of predeterminedI angularity, one of said discs having ratchet teeth with slop# ing leading edges, an operating' member having a pawl lever engaging said ratchet teeth for rotating the same through a' predetermined arc in the same direction with each stroke thereof,

said other disc being provided with clutch teeth projecting radially beyond the teeth of said ratchet disc,- 'a spring-pressed latch member normally engaging said clutch teeth and adapted to be displaced radially by the sloping edges of said ratchet teeth during the initial relative rotation of said discs to facilitate the passing of said latch member from one clutch tooth to the next during the continued unitary rotation of said discs.

8. A mechanical movement for imparting intermittent rotary motion, the combination of a pair of discs rotative about `a common laxis and having limited relative rotation through a small arc of predetermined angularity, one of said I member, said ratchet discl Aacting in the initial relative rotation of said discs to displace said latch member radially outward from the base of said clutch teeth and 'thereby permitting the same to pass from one clutch tooth to the next in the continued unitary rotation of said disc during each stroke of said pawl lever.

CHARLES HTAYLOR. 

